Add accidentally removed \end{description} back in.
diff --git a/Doc/lib/libundoc.tex b/Doc/lib/libundoc.tex
index 9f959c4..8e99393 100644
--- a/Doc/lib/libundoc.tex
+++ b/Doc/lib/libundoc.tex
@@ -70,6 +70,7 @@
 \item[\module{toaiff}]
 --- Convert "arbitrary" sound files to AIFF files; should probably
 become a tool or demo.  Requires the external program \program{sox}.
+\end{description}
 
 
 \section{Obsolete \label{obsolete-modules}}